1. Field of the Invention
This invention relates generally to telecommunication services, and, more specifically to a system and method for providing telecommunication services across networks that use different protocols.
2. Description of Background Art
In many conventional telecommunication networks that provide wireless telecommunication services, such as ANSI-41 and GSM networks, each mobile phone user is associated with a Mobile Switching Center (MSC) that is referred to as a user""s xe2x80x9chome MSC.xe2x80x9d A mobile phone user""s home MSC receives all calls for the user and either (1) routes the calls to the user if the user is within the coverage area of the home MSC or (2) if the user is not within the coverage area of the home MSC, routes the calls to the MSC at which the user is currently registered (the xe2x80x9cserving MSCxe2x80x9d), where the serving MSC then routes the calls to the user.
In conventional ANSI-41 and GSM networks, each MSC is associated with a Home Location Register (HLR), a Visitor Location Register (VLR) and an Authentication Center (AuC). The functions of an AuC include storing authentication information for mobile phone users whose home MSC is the MSC associated with the AuC. The functions of an HLR include storing profiles of users whose home MSC is the MSC associated with the HLR and, for each of such users, storing the identity of the MSC at which the user is currently registered. The functions of VLR include storing users profiles of roaming users temporarily registered at the MSC associated with the VLR.
When a user roams out of the territory of his home MSC and into the territory of a serving MSC, the VLR of the serving MSC (the xe2x80x9cserving VLRxe2x80x9d) needs to communicate with the HLR of the home MSC (the xe2x80x9chome HLRxe2x80x9d) in order to enable the user to register at the serving MSC and to enable the home MSC to route calls for the user to the serving MSC. For instance, the serving VLR informs the home HLR that the user has requested registration at the serving MSC, and the home HLR sends the serving VLR user profile information. Additionally, when the home MSC receives a call for the user, the serving VLR sends the routing number of the serving MSC to the home HLR, which enables the home MSC to route the call to the serving MSC.
Due to the variety of portable telecommunication devices, it is not uncommon for customers to subscribe to telecommunication services that are provided by multiple telecommunication networks. A customer may subscribe to multiple telecommunication networks that each cover a distinct and separate service area or that have overlapping service areas, as is the case if a customer subscribes to a satellite based system and an ANSI-41 based system both having broad service coverage in North America. In some cases the customer may use a device that is capable of working in multiple networks, such as a dual mode mobile phone that supports two of the wireless air interface standards commonly used in North America (e.g., PCS1900 and TDMA standards), or the customer may use multiple devices where each device operates in a specific telecommunications network. Customers may require access to telecommunication services from one network at a time or from multiple networks simultaneously depending on their current geographic location and the service coverage of the telecommunications networks to which they subscribe.
As indicated above, in order to provide seamless services to customers as they travel or switch between different networks, various HLRs and VLRs in the different networks need to communicate with each other. However, this can be problematic because many of the telecommunication networks use different protocols for communications between the HLRs, VLRs, AuCs, and MSCs within their own networks. For instance, many North American networks use the ANSI-41 protocol and many European networks use the GSM protocol. Therefore, it is necessary to enable networks that use different protocols to communicate with each other in order to provide seamless service to customers as they move between these networks.
There are known methods for enabling communication between disparate networks that use different protocols. One such method, which is described in U.S. Pat. No. 5,862,481, provides an Inter-Technology Roaming Proxy (IP) that translates requests from one network to another. One problem with this method is that if many networks are involved, a lot of additional equipment is required. For N networks, the number of IPs required is N(Nxe2x88x921). For example, two networks require two (2) IPs, and four networks require twelve (12) IPs. Additionally, this method fails to provide a way to manage feature and service interactions when a customer has simultaneous access to telecommunications services from multiple networks.
Therefore, it is desirable to provide seamless services to customers as they roam into disparate networks without using as much equipment as known methods for providing such services. Additionally, it is desirable to manage feature and service interactions for customers that have simultaneous access to telecommunication services in multiple networks.
The present invention provides a method and system for providing seamless, wireless telecommunication services to customers that move between disparate networks. A Universal Location Service Register (ULSR) communicates and provides mobility management and authentication functions across networks that use different protocols. Instead of each MSC communicating with its own HLR and AuC to exchange user information, each MSC communicates with the ULSR to exchange such information, thereby eliminating the need for associating each MSC with its own HLR and AuC. The ULSR communicates with the MSCs in each network serviced by the ULSR in accordance with the protocol of that network. The ULSR store user profiles that may include the identity of the user, authentication information for the user""s mobile phone, a list of networks the user is authorized to access, and the identity of the MSC at which the user is currently registered.
When a user roams into a network other than the user""s home network and requests registration at an MSC in the such network (the xe2x80x9cserving networkxe2x80x9d), the MSC (the xe2x80x9cserving MSCxe2x80x9d) notifies the ULSR that the user has requested registration. The ULSR determines whether the user can be registered at the serving MSC, and, if so, authorizes the registration. When a call is received for the user at an MSC in the user""s home network, the home MSC sends a request for the routing number to the ULSR. The ULSR retrieves the user""s profile and determines that the user is registered at the serving MSC. The ULSR sends a request for a routing number to the serving MSC, and the serving MSC provides the ULSR with a routing number. The ULSR then sends the routing number to the home MSC, and the home MSC routes the call to the serving MSC, which routes the call to the user. The ULSR communicates with the home network in accordance with the protocol used by the home network, and the ULSR communicates with the serving network in accordance with the protocol used by the serving network.
In one embodiment, the ULSR also manages feature and service interactions for customers. For instance, the ULSR may determine, based on the user""s profile, whether a user is subscribed to call waiting or call forwarding service and then instruct the applicable MSC accordingly. In yet another embodiment, if a user is simultaneously registered in multiple networks, the ULSR will use information stored in the user""s profile and/or internal logic to determine to which network a call for the user should be forwarded.
Therefore, the present invention provides seamless service to wireless device users as they roam across multiple networks while reducing the amount of equipment used by known methods. Additionally, according to one embodiment, the present invention manages feature and service interactions for users that have simultaneous access to telecommunication services in multiple networks.